Process for breaking petroleum emulsions



Patented Apr. 20, 1937 lTED STATES PROCESS FOR BREAKING PETROLEUM EMULSIONS Melvin De Groote, St. Louis, and Arthur F. Wirtel, Kirkwood, Mo., assignors to Tretolite Company, Webster Groves, Mo., a corporation of Missouri No Drawing.

Application September 18, 1936,

Serial No. 101,435

7 Claims.

Petroleum emulsions are of the water-in-oil type, and comprise fine droplets of naturallyoccurring waters or brines, dispersed in a more or less permanent state throughout the oil which constitutes the continuous phase of the emulsion. They are obtained from producing wells and from the bottom of oil storage tanks, and are commonly referred to as cut oil, roily oil, emulsified oil and bottom settlings.

The object of our invention is to provide a novel and inexpensive process for separating emulsions of the character referred to into their component parts of oil and water or brine.

Briefly described, our process consists in subjecting a petroleum emulsion of the water-in-oil type to the action of a treating agent or demulsifying agent of the kin-l hereinafter described, thereby causing the emulsion to break down and separate into its component parts of oil and water or brine, when the emulsion is permitted to remain in a quiescent state after treatment, or is subjected to other equivalent separatory procedures.

The treating agent or demulsifying agent contemplated by our process consists of or comprises an alkylated naphthalene sulfonic acid in the form of a polyhydric alcohol ether substituted alkylamine salt of the kind hereinafter described, in which at least one of the alkyl groups substituted in the naphthalene nucleus contains not less than three carbonatoms nd not more than ten carbon atoms. Such products are nuclear substituted products.

Commercial demulsifying agents employed fo breaking or resolving oil field emulsions include, among other substances, substituted polycyclic aromatic sulfonic acids, or their salts. which finds most frequent application is obtained by introducing one, two or more alkyl'groups into a naphthalene residue and then producing the sulfonic acid. Due to the corrosiveness of the sulfonic acid, it is the usual practice to employ the reagent in the form of a salt, such as ammonium salt, potassium salt, sodium salt, etc.

Wehave found that if the alkylated aromatic sulfonic acids of the kind previously referred to are neutralized by means of a polyhydric alcohol ether substituted alkylamine of the kind hereinafter described in detail, one obtains a treating agent or demulsifying agent of unusual effectiveness.

The type In our co-pending application for patent Serial,

No. 101,433, filed September 18, 1936, wehave employed as a demulsifying agent the chemical compound obtained by neutralizing alkylated naphthalene sulfonic acids with l -mono-amyl amino propane-2,3-diol or l-di-amyl amino pr0- pane-2,3-diol, or similar materials of the kind or akin to those disclosed in the aforementioned Olin patent, or similar alkylamino propanol 0r propane-dial compounds of the kind disclosed in Journal of. the American Chemical Society, 52, 1930, pp. 1521 and 1528.

In our co-pending application for patent Serial No. 101,434, filed September 18, 1936, we have disclosed a demulsifying agent obtained by neutralizing alkylated naphthalene sulfonic acids with substituted amines somewhat similar to those described in the Olin patent previously mentioned, but derived from glycols instead of from glycerol. The products employed in the last mentioned co-pending application for neutralizing the alkylated aromatic sulfonic acids consist of hydroxyalkyl-alkylamines, such as hydroxy-ethylamylamine.

The amine derivatives aforementioned which are employed in neutralizing the aromatic sulfonic acids, and thus produce the compounds employed as demulsifying agents in the processes described in our said co-pending applications 'for patents, may be obtained in various manners, but perhaps most conveniently by'reactions between the chlorhydrins derived from either a glycol such as ethylene gylcol, or from gylcerol and a primary or secondary amine, such as amylamine, or di-amylamine.

The methods of manufacture which result in the substituted amines of the kind above described can be applied just as successfully to the conversion of polyhydric alcohol-ethers into the corresponding chlorhydrins. This first step can be followed by subsequent reaction with a primary or secondary alkylamine, such as mono-amylamine or di-amylamine. Glycerol is converted into di-glycerol,-a glycerolether for use in the manufacture of certain kinds of dynamite. Glycerol may be converted into tri-glycerol, or even higher'glycerols. Di-glycerol, for example, is suitably prepared in the manner" described in U. S. Patent No. 1,126,467, dated January 26, 1915,

to Hibbert. The various glycol ethers can be prepared by the same process, or other processes, such as those employed in the manufacture of polyglycerols. Di-ethylene glycol is a commodity available in the open market. Pentaethylene glycol has been prepared having two hydroxyl groups and four ether groups. In the case of polyglycerols, one might even combine glycerol or a polyglycerol with a mono-hydric alcohol, so as to yield an ether which contained at least two hydroxyls.

If any suitable polyhydric alcohol ether containing two or more hydroxyl groups is converted into a chlorhydrin having at least one residual hydroxyl group, then such intermediate When such a product is reacted with monoamylamine or with di-amylamine, reaction takes place with the elimination of hydrogen chloride, which may combine with the unreacted amine or with the substituted amine. Since the chloride is eliminated by subsequent reaction with strong caustic soda, or caustic potash, it will be ignored and the reaction simply illustrated as follows:

product is suitable for reaction with a primary or secondary alkylamine to give the final substituted alkylamine which is used to neutralize the alkylated naphthalene sulfonic acids, so as to result in the demulsifying agent employed in the present process.

The method of manufacturing mono-chlorhydrins or di-chlorhydrins from glycerol is well known. The manufacture of glycerol chlorhydrin and glycerol di-chlorhydrin is described in Organic Syntheses, Collective Volume 1, G11- man, pp. 286 and 288. The same methods may be employed in the manufacture of chlorhydrins from the polyhydric alcohol ethers, except that for use in manufacturing the reagent of the present process, it is not necessary to go through the purification steps, insofar that a product containing the bulk of such chlorhydrins, for instance, 65-75%, may be used, if desired, in place of the purified product. The manufacture of chlorhydrins is equally satisfactory, regardless of whether the polyhydric alcohol ether was derived from a glycol or a glycerol, or. from a glycerol and a glycol, or from a glycerol and a mono-hydric alcohol, or other possible combinations.

Having obtained polyglycol or polyglycerol ether chlorhydrin, containing at least one residual ydroxyl, the next step is the reaction with the alkylamine, so as to produce the substituted alkylamine of the kind contemplated in the present process.

For purposes of illustration, the reactions will be illustrated by the use of (ii-glycerol, as an example, although it is understood that any of the various chlorhydrins of the kind specified without limitation as to any isomeric form, may be used.

Although di-glycerol may occur in three different isomeric forms, it may be illustrated by the following formula:

Such di-glycerol may be converted into either the mono-chlorhydrinor the di-chlorhydrin, in the same manner that glycerol is so converted. For

- purpose of illustration, the reaction involving the mono-chlorhydrin will be described. The monochlorhydrin has the following composition:

Similar reactions involve the substitution of diamylamine for the mono-amylamine.

Other reactions involve two molecules of monoamylamine or two molecules of di-amylamine reacting with one molecule of the di-chlorhydrin, which may be illustrated by the following formula:

Since (ii-glycerol is available commercially, and

since di-ethylene glycol is available commercially, it is our preference to manufacture the demulsifying agent employed in our process from these compounds as raw materials. On many emulsions, the demulsifying agent obtained by using di-glycerol as the raw material for producing the substituted alkylamine appears to be more effective than the corresponding product obtained from (ii-ethylene glycol, and therefore, di-glycerol is the preferred raw material, due to its availability in the open market at low cost.

In the illustrations previously referred to, reference has been made to mono-amylamine and diamylamine, since this alkylamine is available in the open market at the lowest price. Any other suitable alkylamine. and particularly, alkylamines having at least four carbon atoms and not more than eight carbon atoms, are equally suitable. It

is known, of course, that various primary and for reaction with the chlorhydrins of the kind described. The alkylamine include the amines described more fully in Thorpe Dictionary of Applied Chemistry, vol. 1, p'. 188 (1921).

Piperidine (hexahydro-pyridine) is not a true aliphatic amine from the strictest structural standpoint, but is commonly recognized as having the properties of an aliphatic amine. Hence, it

I is intended that piperidine be included in the broad classification of alkylamines. Smith, A

Textbook of Organic Chemistry, 1932,. second edition, revised, p. 646, states as follows: f'Whereas, pyridine is a weak tertiary base of aromatic character, piperidine is a strong secondarybase, the entire behaviour of which classifies it with the aliphatic amines. 7

There does not appear to be any suitable explanation of the unusual superiority of the de-. -mulsifying agent employed in the present process,

and similarly, there does not seem to be any basis by which one could anticipate or foresee this unusual effectiveness. Apparently, this marked improvement is not directly related to oil orwater solubility, insofar that similar neutralization with cohol ether residue, that is, polyhydric alcohol ether minus one or more hydroxyls". The statement is obvious when one notes the structure of the examples previously illustratedby graphical formulas. I

Apparently, there is some unlocked-for cooperation or chemical or 'physico-chemicai relationship between the polyhydric alcohol ether substituted alkylamine residue and the polycyclic sulfo-aromatic residue. The neutralization of other conventional acidic demulsifying reagents with polyhydric alcohol ether substituted alkylamines doesnot seem to produce 'anymarked improvement over the corresponding sodium or ammonium salts, and in many cases, yields an inferior product, thus indicating thatapparently the increased value does not reside in an'additive effect, due to the polyhydric alcohol ether substituted alkylamine residue. If one neutralizes other sulfonio acids, which are known to be effective demulsifying agents, such as petroleum sulfonic acids of the mahogany acid type, with a polyhydric alcohol ether substituted alkylamine, one does not obtain a more effective demulsifying agent, and indeed, one is more likely to obtain a demulsifying agent which is less effective. Based on the results of actual tests obtained in a variety of emulsified crudes occurring in a number of the major oil fields of the United States, the conclusion one must inevitably reachis, that the result obtained by uniting the two residues, 1. e., the polyhydric alcohol ether substituted alkylamine residue and the described polycyclic sulfo-aromatic residue in a single molecule, results in an unlocked-for, unique quality. which could not be foreseen by the present knowledge of the art, and which produces a demulsifying agent that is particularly effective for a large number. of emulsified crude oils.

Al-kylated naphthalene sulfonic acids are produced commercially, and the salts are used for a'variety of purposes. They are generally produced from naphthalene, because there does not appear to be any advantage in the use of a naphthalene derivative, such as chlornaph'thalene, alpha, and beta naphthol, etc. In other-words, one could introduce the sulfonic acid residue and the alkyl residues into a substituted naphthalene, such as chlor-naphthalene, etc., just as readily perhaps, as in the case of naphthalene. Such simple derivatives, of course, are the chemical equivalent of naphthalene in the manufacture of such sulfonic acids as are employed in the manufacture of the present reagent. It is understood that the word naphthalene is hereinafter employed-to include these derivatives.

The general process of manufacturing'the demulsifying agent contemplated by our process,

- consists in converting the naphthalene into either the alpha or beta naphthalene sulfonic acid, or a mixture of the same, or in some instances, into a dior even a tri-sulfonic acid, or a mixture of the various types, In most instances there is no advantage in introducing more than one sulfonic acid residue. In many instances it is unnecessaryfto use particular care to prepare either only the alpha suIfonIc-"acid, or either only the beta sulfonic acid, because a mixture in which either one or the other predominates, or a mixture inwhich the alpha and beta sulfonic acids are present in approximately equal amounts, is

just as satisfactory as one sulfonic acid completely freed from the other type.

The alcohol employed, such as propyl alcohol,

butyl alcohol, amyl alcohol, hexyl alcohol, decyl' alcohol, etc., is converted into the acid "sulfate, such as propyl hydrogen sulfate, etc. The naphthalene sulfonic acid and the alkyl hydrogen sulfate are combined in proportions so that one,

two, three, or even four alkyl groups are introduced into the aromatic residue. This condensation' reaction is generally carried'out in the presence of an excessof sulfuric acid. Injsome inkylated and tri-alkylated material appear to yield the most desirable type of reagent. The presence of some mono -alkylated material, or some tetraalkylated material is not objectionable, and may even be desirable.

It is obvious, of course, that the alkylated groups introduced mightbe derived from olefines, such as butylene, propylene, amylene, etc., insofar that such oleflnes react directly with sulfuric acid, to produce the alkyl hydrogen sulfates. Q1 course, .in addition to introducing such alkyl residues of the kind described into the aromatic nucleus, one could also introduce an alkyl residue from some other alcohol, as, for example, an alkylated group derived from ethyl or methyl alcohol, or one might introduce a group derived from an aryl, aralkyl, hydroaromatic, or cycloalcohol or the like, but regardless of whether or not onefintroduces such other residues, it is necessary that at least one alkyl residue of the kind described, 1. e., having at least three carbon atoms and not more than ten carbon atoms, be introduced'into the naphthalene ring. Such compoundshaving some other residue present, such as a methyl residue, might be considered stances, the various reactions, such as sulfonation, sulfation, condensation, etc. are carried out simultaneously. Generally speaking, the di-alas being derived from methyl naphthalene, in-

hol employed, or the particular isomeric form of the alcohol employed, although generally speaking, it is most desirable to use the one lowest in cost. It is immaterial whether one uses normal propyl alcohol or isopropyl alcohol. It is immaterial whether one uses a normal butyl or isobutyl alcohol. ,It is immaterial whether the alcohol be a primary alcohol, or a secondary alcohol, or a tertiary alcohol, or the like.

It is obvious that a large number of isomers can be produced in the manufacture of the reagent employed in the present process. For instance, although the sulfonic group may be introduced into either the alpha or beta position, it is manifest that the alkyl group or groups can be introduced into various positions in regard to the position of the sulfonic acid residue. Apparently, as far as we are aware, one isomeric form is as effective as the other. Reference to the compounds is not intended to indicate any particular isomer, unless the text clearly indicates some specific position.

Insofar that the most readily available alcohols, from the standpoint of cost, are isopropyl alcohol, normal butyl alcohol, isobutyl alcohol, and amyl alcohol, it is our preference to produce our reagents from these alcohols, and in some instances, it is desirable to introduce different alkyl'groups, such as a propyl group and butyl group, into the same sulfo-naphthalene residue.

In the actual manufacture of alkylated naphthalene sulfonic acids, the completion of the desired chemical reactions is followed by a washing process which removes the excess of sulfuricacid or other sulfonation, sulfation, or condensation reagent employed. The acidic mass thus obtained is neutralized with a polyhydric alcohol ether substituted alkylamine in the same manner that sodium or potassium or ammonium hydroxides might usually be employed. The final product, if it represents a pasty or semi-solid or a solid mass, is rendered suitable for industrial use by the addition of a solvent, such as water, an alcohol, a coal tar solvent, a petroleum hydrocarbon solvent, or in any similar manner.

The demulsifying agent that we prefer to use in practising our process is obtained by a reaction in which three molecules of isopropyl alcohol are united with one molecule of naphthalene by the customary sulfation, sulfonation and condensation reactions. The resulting mixture consists largely of di-propyl naphthalene sulfonic acids and tri-propyl naphthalene sulfonic acids, with possibly small amounts of monopropyl sulfonimacids and tetra-propyl sulfonic acids present. Generally speaking, it is easier to conduct the reaction so that the bulk of the sulfonic acid represents the beta type, although the alpha type may be produced, if desired. The product is neutralized with di-glycerol ether mono-amylamine obtained in the manner previously described, and by reaction between diglycerol mono-chlorhydrin and mono-amylam'ine. The product so obtained is diluted with one or more solvents, so as to reduce its viscosity to that of ordinary castor oil, or slightly greater.

The solvents which we preferably employ are a naphthalene sulfonic acids, tri-isopropyl naphthalene sulfonic acids, mono-normal butyl naphthalene sulfonic acids, di-normal butyl naphthalene sulfonic acids, mono-isobutyl naphthalene sulfonic acids, di-isobutyl naphthalene sulfonic acids, mono-amyl naphthalene sulfonic acids, di-amyl naphthalene. sulfonic acids, triamyl naphthalene sulfonic acids, mono-hexyl naphthalene sulfonic acids, dl-hexyl naphthalene sulfonic acids, tri-hexyl naphthalene sulfonic acids, mono-octyl naphthalene sulfonic acids, dioctyl naphthalene sulfonic acids, mono-decyl naphthalene sulfonic acids, di-decyl naphthalene sulfonic acids, mono-isopropyl di-normal butyl naphthalene sulfonic acids, di-isopropyl di-nor- It may be desirable to indicate that there is sometimes some variation in nomenclature in regard to the salts derived from strong acids and various amines. For instance, the combination of aniline, and hydrochloric acid, is often referred to as aniline hydrochloride. When aniline hydrochloride is treated with caustic soda, aniline is regenerated and sodium chloride is formed.

For this reason, and perhaps for other reasons, structural conditions are best expressed by referring to the compound as a hydrochloride, in order to indicate that one does not obtain the chloride of a quaternary ammonium compound. Similarly, the reaction of a polyhydric alcohol ether substituted alkylamine with a sulfonic acid may be considered as producing the polyhydric alcohol ether substituted alkylamine salt, although for reasons pointed out, such salt might be looked upon as a polyhydric alcohol ether substituted alkylamine hydrogen sulfonate, as well as being considered as a polyhydric alcohol ether substituted alkylaminesulfonate. Insofar that it is perfectly clear as to the chemical com-' position of the compound, it is immaterial which nomenclature is employed.

In such instances where there is present more than one sulfonic acid residue, as in the formation of a di-sulfonic acid, or a tri-sulfonic acid, or a tetra-sulfonic acid, if desired, all the sulfonic acid hydrogen may be neutralized with a polyhydric alcohol ether substituted alkylamine, and the other sulfonic hydrogen atom or atoms may be neutralized with some other suitable base, such as sodium hydroxide, potassium hydroxide, ammonium hydroxide, etc.

Polyhydric alcohol ether substituted alkylamine salts, such as the hydrochloride, may react by double decomposition with alkali sulfonates in a suitable medium to produce the polyhydric alcohol ether substituted alkylamine sulfonate.

It is to be noted that the present process employs alkylated naphthalene sulfonic acids of the kind described, which have been neutralized with polyhydric alcohol ether substituted alkyl amines of the kind previously described, and which may be indicated by the following formula:

in which T is a hydrocarbon group, B is an alkyl radical, m represents the numeral one or more, n represents the numeral 1 or 2, n represents the numeral zero or one, and m' represents the numeral 1 or 2, with the proviso that 12 plus 11. plus m equals 3.

If the alkylated naphthalene sulfonic acid in whichat least one alkyl group containing at least three carbon atoms and not more than ten carbon atoms has been introduced into the naphthalene nucleus, is indicated by ,the formula H-D-(SO3)m" then the chemical compounds used in the present process may be indicated by the type formula in which m represents the numeral 1, 2 or in which the various other characters have their previous significance.

Conventional demulsifying agents employed in the treatment of oil field emulsions are used as such, or after dilution with any suitable solvent, such as water, petroleum hydrocarbons, such as gasoline, kerosene, stove oil, a coal tar product,

such as benzene, toluene, xylene, tar acid 011, cresol, anthracene oil, etc. Alcohols, particularly aliphatic alcohols, such asmethyl alcohol, ethyl alcohol, denatured alcohol, propyl alcohol, butyl alcohol, hexyl alcohol, octyl alcohol, etc., may be employed as diluents. Miscellaneous solvents, such as pine oil, carbon tetrachloride/sulfur dioxide extract obtained in the refining of petroleum, etc. may be employed as diluents. Similarly, the

. material or materials employed as the demulsifying agent of our process may be admixed with one or more of the solvents customarily used in connection with conventional demulsifying agents. Moreover, said material or materials may be used alone or in admixture with other suitable well known classes of demulsifying agents, such as demulsifying agents of the modified fatty acid type, the petroleum sulfonate type, the alkylated sulfa-aromatic type, in which the I sulfonic hydrogen is neutralized by the use of same base other than polyhydric alcohol ether substituted alkylamines.

it is well known that conventional demulsifying agents may be used in a water-soluble form, or in an oil-soluble form, or in a form exhibiting both oil and water solubility. Sometimes they may be used in a form which exhibits relatively limited water solubility and relatively limited oil solubility. However, since such reagents are sometimes used in a'ratio of 1 to 10,000 or 1 to 20,000, or even 1 to 30,000, such an apparent insolubility in oil and water is not significant, because said reagents undoubtedly have solubility within the concentration employed. This same fact is true in regard to the material or .materials employed as the demulsifying agent of our process.

We desire to point out that the superiority of the reagent or demulsifying agent contemplated in our procesris based upon its ability to treat certain emulsions more advantageously and at a somewhat lower cost than is possible with other available demulsifiers, or conventional mixtures thereof. It is believed that-the particular demulsifying agent or treating agent herein described will find comparatively limited application, so far as the majority of oil field emulsions are concerned; but we have found that such a demulsifying agent has commercial value, as it will economically break or resolveoil field emulsions in a number of cases which cannot be treated as easily or at so low a cost with the demulsifying agents heretofore available.

Having thus described our invention, what we claim as new and desire to secure by Letter Patent is:

1. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising a polyhydric alcohol ether in which T is a hydrocarbon radical, B is an alkyl radical, D(SOa)n1" is a residue derived from an alkylated naphthalene sulfonic acid residue,

in which at least one alkyl group containing at least three carbon atoms and not more than ten carbon atoms has been introduced into the naphthalene nucleus, m represents the numeral 1 or more, n represents the'numeral 1 or 2, n represents the numeral zero or 1, m represents the numeral 1or 2, with the proviso that 11. plus 1!. plus 112. equals 3 and m" represents the numeral 3. A .process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion tol the action of a demulsifying agent comprising a}. polyhydric alcohol ether substituted alkylamine salt of an alkylated naphthalene mono-sulfonic acid, in which at least one alkyl group substituted in the naphthalene nucleus contains at least three carbon atoms and not more than ten carbon atoms.

4. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising apolyhydric alcohol ether substituted alkylamine salt of a butylated naphthalene mono-sulfonic acid.

5. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent comprising a polyhydric alcohol ether substituted alkylamine salt of an amylated naphthalene mono-sulfonic acid.

' 6. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to' the action of a demulsifying agent comprising a polyhydric alcohol ether substituted alkylamine salt of a propylated naph-- thalene mono-sulfonic acid.

'7. A process for breaking petroleum emulsions of the water-in-oil type, which consists in subjecting the emulsion to the action of a demulsifying agent obtained by converting naphthalene into the mono-sulfonic acid; converting propyl alcohol into the acid sulfate; combining said materials in molecular proportions in presence of sulfuric acid as a condensing agent; followed by the conventional washing process and separation of the aqueous waste acid and neutralization of the sulfonic acid by means of di-glycerol ether substituted mono-amylamine, followed by addition of a suitable solvent.

MELVIN DE GROOTE. 

